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From: dell@pmday_1.Dayton.NCR.COM (Jim Dell)
Newsgroups: comp.databases,ncr.databases
Subject: Replicating Databases
Message-ID: <679@pmday_1.Dayton.NCR.COM>
Date: 14 Feb 90 14:43:13 GMT
Reply-To: dell@pmday_1.Dayton.NCR.COM (Jim Dell)
Organization: NCR Corporation, USG Product Marketing, Dayton
Lines: 27


In article <275@gollum.UUCP> wasmith@ncrcae.Columbia.NCR.COM (Wayne A. Smith) 
>Are there any existing databases (products or research
>prototypes) that feature replication? That is, are there
>any databases that allow two copies on a network to be
>maintained strongly consistent with each other? When one
>is updated, that change is propagated to its copy(ies).
>  

The NCR 9800 Data Base System Relational (DBSR) features 
mirroring.  But in the true sense of your question it is not a 
network data base like TOTAL or probably as you mean 
geographically distributed.  This is a planned
enhancement.

Another option of the 9800 is UNION.   UNION is a 
software/hardware combination allowing the 9800 and a NCR Tower 
to exist in the same system and communicating over the system 
bus.  With this system, mirroring is possible.   As far as we    
know any UNIX-based data base can be mirrored using UNION. 


-- 
  Jim Dell                                      e-mail:                        
  NCR Corporation                               Jim.Dell@dayton.NCR.COM       
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